GMNA GM9741P PDF

1 SCOPE.

This test method describes the application of a spectrophotometer or colorimeter to measure color difference between standards and samples based on CIELAB color space. CIELAB is a three dimensional color space containing lightness-darkness (L*), Redness-Greeness (A+) and Yellowness-Blueness (B*) axes. The light source selected for the measurement is Illummant D which is an approximation to daylight. Once the color measurement is completed, the data can be checked with the established color tolerance The tolerance is unique for each color and can be expressed by a mathematical formula.